Out of non-volatile memories, an MRAM (Magnetoresistive Random Access Memory) which uses a change of magneto-resistance has a possibility as a RAM capable of high-speed operation. A cell structure of a conventional MRAM comprises one tunnel magneto-resistance element TMR, a selective transistor MCT for reading, writing word lines WWL, bit lines BL, and source lines SL. As shown in FIG. 28, the tunnel magneto-resistance element TMR has at least two magnetic layers. One of the two layers is a fixed layer PL in which a direction of a spin is fixed, and the other layer is a free layer FL in which a direction of a spin has two states; a parallel state or an anti-parallel state with respect to the fixed layer. Information is memorized depending upon the spin direction of the free layer; the electric resistance of the tunnel magneto-resistance element is set to a high resistance in an anti-parallel state, and the resistance is set to a low resistance in a parallel state. In a reading operation, the degree of resistance of the tunnel magneto-resistance element TMR is read. On the other hand, in a writing operation, a current is made to flow through the writing word lines WWL and the bit lines BL, so that a synthetic magnetic field is excited at the tunnel magneto-resistance element TMR, and as a result, the spin direction of the free layer is controlled. However, the writing operation has a problem that as a shrink of the tunnel magneto-resistance element TMR is advanced, the current which flows through the writing word lines and the bit lines is increased, because the strength of the magnetic field required for writing is increased. On the other hand, an MRAM (Spin RAM) which uses a spin-transfer torque switching technology which changes the spin direction of the free layer by making the current to flow vertically through the tunnel magneto-resistance element TMR, is introduced in “2005 International Electron Device Meeting Technical Digest Papers” pp. 473-476 SpRAM (Non-Patent Document 1). As shown in FIG. 29, this writing method enables the spin direction of the free layer to be controlled with the current which flows vertically through a fixed layer, a tunnel film, and a free layer. Therefore, the current required for writing is proportional to the size of the tunnel magneto-resistance element TMR, and thereby, the writing current can be reduced along with the advance of shrink, as a result, the method is excellent in scalability.